An adjustable damping valve device known from US2013/0340865 has a pressure-dependent auxiliary damping valve which is connected in series upstream of an adjustable main stage valve. The auxiliary damping valve has a construction such as that used in bottom valves, known per se. A damping valve body has separate through-channels for the two throughflow directions which are at least partially covered on their outlet side in each instance by at least one valve disk. A central fastening bolt fixes the valve disks at their inner diameters.
At least one valve disk facing in the direction of the main stage valve is guided radially by a separate centering ring. An auxiliary damping valve body and the centering ring are radially and axially fixed in a tubular housing which is in turn fastened to a piston which is connected to an outer housing of the damping valve device via a connection sleeve.
The valve disk facing in direction of the main stage valve is preloaded by a valve spring supported at an annular cover. The serial arrangement of the auxiliary damping valve body and centering ring induces a summing of manufacturing tolerances which determine the axial installation space for the valve spring and accordingly the preloading or closing force. Ultimately, the damping force characteristic of the auxiliary damping valve is dependent on the closing force of the valve spring.
A further disadvantage of the construction principle consists in that the centering ring is radially supported at the tubular housing. Consequently, an inner wall of the tubular housing must be manufactured in a very precise manner because otherwise a leakage gap can occur under some circumstances between the tubular housing on the one hand and the auxiliary damping valve body and centering ring on the other hand.
It is thus an object of the present invention to overcome the manufacturing problem known from the prior art in connection with the auxiliary damping valve.